Integration of Somfy blinds with KNX and RTS

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It is possible to control a wide range of Somfy motorised blinds with a KNX control system, however there are different solutions depending on the blinds installed. Proprietary RTS wireless control from Somfy can be integrated into a KNX system, though with added complication compared to standard wired technology 230V motors. So, the obvious advice is to keep it simple if possible, but if not, then here are some tips, starting with the direct control method.

1. Typical direct control of motors

230V or 24V motors, Somfy or others, are wired directly to KNX actuators, typically mounted in the distribution board (3wire from KNX actuator to each blind for 230V (common and 2 x switched live) or 2wire for 24V (reverse polarity for direction)).

Blinds actuators are controlled with an UP/DOWN telegram which begins the travel of the motor in either direction. The travel is stopped using a STOP telegram. Blind motors have internal limit switches to allow for overrun.

This method is simple and the most commonly used in KNX installations.

2. RS485 motors

Control Somfy motors that have RS485 connection on the motor direct from a KNX bus using a Somfy KNX interface. The KNX RS485 Motor Controller enables the controlling of up to 18 motors. The motors can be controlled either individually or by groups. RS485 motors can be connected via bridging adapter. Different motor types can be used. Fine tuning of the blind heights on site may require an RS485 Setting Tool

1860286 KNX RS485 Motor Controller Wall Mount (new product)

3. Somfy RTS controlled blinds

Where Somfy RTS (wireless) controlled motors are included in a project that you want to control from KNX, there are two options.

3a. Using Somfy contact closure input devices

For small numbers of motors, the 1-channel "Somfy Busline Transmitter" and 5-channel "Somfy DCT2RTS" can be used together with a suitably configured KNX switching actuator and some logic to achieve one-way control.

3b. Using Somfy RS485 to RTS Transmitter

For larger numbers of motors, you will probably require the Somfy RS485 to RTS interface https://service.somfy.com/down... controlled by a KNX device with RS485 output such as the Arcus KNX-GW-RS232-RS485